package utils;

import java.io.UnsupportedEncodingException;

/**
 * 获取汉语字符串的首字母
 * @ClassName: GetInitial 
 * @Description: TODO
 * @author: wangsm
 * @date: 2016年3月30日 下午10:15:09
 */
public class GetInitial {
	private final static int[] li_SecPosValue = { 1601, 1637, 1833, 2078, 2274,  
        2302, 2433, 2594, 2787, 3106, 3212, 3472, 3635, 3722, 3730, 3858,  
        4027, 4086, 4390, 4558, 4684, 4925, 5249, 5590 };  
	private final static String[] lc_FirstLetter = { "a", "b", "c", "d", "e",  
	        "f", "g", "h", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s",  
	        "t", "w", "x", "y", "z" };  
	
	/** 
	 * 取得给定汉字串的首字母串,即声母串 
	 * @param str 给定汉字串 
	 * @return 声母串 
	 */  
	public String getAllFirstLetter(String str) {  
	    if (str == null || str.trim().length() == 0) {  
	        return "";  
	    }  
	
	    String _str = "";  
	    for (int i = 0; i < str.length(); i++) {  
	        _str = _str + this.getFirstLetter(str.substring(i, i + 1));  
	    }  
	
	    return _str;  
	}  
	
	/** 
	 * 取得给定汉字的首字母,即声母 
	 * @param chinese 给定的汉字 
	 * @return 给定汉字的声母 
	 */  
	public String getFirstLetter(String chinese) {  
	    if (chinese == null || chinese.trim().length() == 0) {  
	        return "";  
	    }  
	    chinese = this.conversionStr(chinese, "GB2312", "ISO8859-1");  
	
	    if (chinese.length() > 1) // 判断是不是汉字  
	    {  
	        int li_SectorCode = (int) chinese.charAt(0); // 汉字区码  
	        int li_PositionCode = (int) chinese.charAt(1); // 汉字位码  
	        li_SectorCode = li_SectorCode - 160;  
	        li_PositionCode = li_PositionCode - 160;  
	        int li_SecPosCode = li_SectorCode * 100 + li_PositionCode; // 汉字区位码  
	        if (li_SecPosCode > 1600 && li_SecPosCode < 5590) {  
	            for (int i = 0; i < 23; i++) {  
	                if (li_SecPosCode >= li_SecPosValue[i]  
	                        && li_SecPosCode < li_SecPosValue[i + 1]) {  
	                    chinese = lc_FirstLetter[i];  
	                    break;  
	                }  
	            }  
	        } else // 非汉字字符,如图形符号或ASCII码  
	        {  
	            chinese = this.conversionStr(chinese, "ISO8859-1", "GB2312");  
	            chinese = chinese.substring(0, 1);  
	        }  
	    }  
	
	    return chinese;  
	}  

	/** 
	 * 字符串编码转换 
	 * @param str 要转换编码的字符串 
	 * @param charsetName 原来的编码 
	 * @param toCharsetName 转换后的编码 
	 * @return 经过编码转换后的字符串 
	 */  
	private String conversionStr(String str, String charsetName,String toCharsetName) {  
	    try {  
	        str = new String(str.getBytes(charsetName), toCharsetName);  
	    } catch (UnsupportedEncodingException ex) {  
	        System.out.println("字符串编码转换异常：" + ex.getMessage());  
	    }  
	    return str;  
	}  
}
